19978378 has 16 divisors (see below), whose sum is σ = 34948800. Its totient is φ = 8561868.

The previous prime is 19978373. The next prime is 19978381. The reversal of 19978378 is 87387991.

It is not an unprimeable number, because it can be changed into a prime (19978373) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13876 + ... + 15247.

It is an arithmetic number, because the mean of its divisors is an integer number (2184300).

Almost surely, 2^19978378 is an apocalyptic number.

19978378 is a deficient number, since it is larger than the sum of its proper divisors (14970422).

19978378 is an equidigital number, since it uses as much as digits as its factorization.

19978378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29146 (or 29132 counting only the distinct ones).

The product of its digits is 762048, while the sum is 52.

The square root of 19978378 is about 4469.7178881894. The cubic root of 19978378 is about 271.3439078249.

The spelling of 19978378 in words is "nineteen million, nine hundred seventy-eight thousand, three hundred seventy-eight".